“All those years ago,” NPR reported earlier this week, “as potters continued to throw clay, the molten iron that was rotating deep below them tugged at tiny bits of magnetic minerals embedded in the potters’ clay. As the jars were heated in the kiln and then subsequently cooled, those minerals swiveled and froze into place like tiny compasses, responding to the direction and strength of the Earth’s magnetic field at that very moment.”

Archaeologist Erez Ben-Yosef, one of the researchers on the project, has compared the process to a terrestrial “tape recorder,” and a particularly sensitive one at that: the resulting jars “provide an unprecedented look at the planet’s magnetic field over those six centuries, one that’s much harder to get from rocks.”

These accidental indices also indicate that the Earth’s magnetic field at the time was much stronger than expected; ominously, this “astonishing geomagnetic spike,” as mentioned above, could happen again. Indeed, the jars have “given scientists a glimpse of how intense the magnetic field can get—and the news isn’t good for a world that depends on electrical grids and high-tech devices,” Annalee Newitz writes for Ars Technica.

“The researchers note that this geomagnetic spike is similar to another that occurred in the 10th century BCE,” Newitz adds. “Data from the 10th century spike and this 8th century one indicate that such events were probably localized, not global. That said, they write that ‘the exact geographic expanse of this phenomenon has yet to be investigated, and the fact that these are very short-lived features that can be easily missed suggests that there is much more to discover.’”

This vision—of highly localized, mysterious geomagnetic storms frying electronics from below—is not only a great plot device for some burgeoning scifi novelist, it could also almost undoubtedly be weaponized: subterranean geomagnetic warfare against an entire region of the planet, short-circuiting every electrical device in sight.

Of course, it’s also worth noting that this would still be happening: that is, today’s ceramics should still be “recording” the Earth’s magnetic field, even without any corresponding spike in that field’s strength. An invisible terrestrial forcefield is thus still inscribing itself inside objects in your kitchen cabinet or standing on your breakfast table. Everyday knick-knacks in retail stores around the world are still archives of planetary magnetism.

This also makes me wonder what other types of artifacts—clay figurines from nomadic Arctic tribes, mud bricks from central Africa—might also house geomagnetic records yet to be analyzed by modern technology. So what else might be discovered someday?

I’m reminded of the possibility that space weather—or “fossils of spacetime”—might be frozen into the built environment in the form of GPS glitches: hidden inside minute structural errors in large building projects, such as freeways, dams, and bridges, there might be evidence that our solar system is passing through “cosmic kinks” of dark matter.

An interesting new paper suggests that the ritual practice of burning parts of villages to the ground in southern Africa had an unanticipated side-effect: resetting the ground’s magnetic data storage potential.

As a University of Rochester press release explains, the “villages were cleansed by burning down huts and grain bins. The burning clay floors reached a temperature in excess of 1000ºC, hot enough to erase the magnetic information stored in the magnetite and create a new record of the magnetic field strength and direction at the time of the burning.”

What this meant was that scientists could then study how the Earth’s magnetic field had changed over centuries by comparing more recent, post-fire alignments of magnetite in the ground beneath these charred building sites with older, pre-fire clay surrounding the villages.

The ground, then, is actually an archive of the Earth’s magnetic field.

If you picture this from above—perhaps illustrated as a map or floor plan—you can imagine seeing the footprint of the village itself, with little huts, buildings, and grain bins appearing simply as the outlines of open shapes.

However, within these shapes, like little windows in the surface of the planet, new magnetic alignments would begin to appear over decades as minerals in the ground slowly re-orient themselves with longterm shifts in the Earth’s magnetic field, like differently tiled geometries contrasting with the ground around them.

What really blows me away here, though, is the much more abstract idea that the ground itself is a kind of reformattable magnetic data storage system. It can be reformatted and overwritten, its data wiped like a terrestrial harddrive.

While this obviously brings to mind the notion of the planetary harddrive we explored a few years ago—for what it’s worth, one of my favorite posts here—it also suggests something quite strange, which is that landscape architecture (that is, the tactical and aesthetic redesign of terrain) and strategies of data management (archiving, cryptography, inscription) might someday go hand in hand.

Or we could install upside-down periscopes on the sidewalks of NYC so pedestrians can peer into subterranean infrastructure, exploring subways, cellars, and buried streams. Franchise this to London, Istanbul, and Jerusalem, scanning back and forth through ruined foundations.

Holograph-bombs—ArchaeoGrenades™—that spark into life when you throw them, World of Warcraft-style, out into the landscape, and the blue-flickering ancient walls of missing buildings come to life like an old TV channel, hazy and distorted above the ground. Mechanisms of ancient light unfold to reveal lost architecture in the earth.

[Image: An LED cube by Pic Projects, otherwise unrelated to this post].

Or there could be football-field-sized milling machines that re-cut and sculpt muddy landscapes into the cities and towns that once stood above them. A peat-bog miller. Leave it operating for several years and it reconstructs whole Iron Age villages in situ.

Simultaneous milling/scanning devices that bring into being the very structures they claim to study. Ancient fortifications 3D-printed in realtime as you scan unreachable sites beneath your city’s streets.

Deep-earth projection equipment that impregnates the earth’s crust with holograms of missing cities, outlining three-dimensional sites a mile below ground; dazed miners stumble upon the shining walls of imaginary buildings like a laser show in the rocks around them.

Or a distributed iPhone app for registering and recording previously undiscovered archaeological sites (through gravitational anomalies, perhaps, or minor compass swerves caused by old iron nails, lost swords, and medieval dining tools embedded in the ground). Like SETI, but archaeological and directed back into the earth. As Steven Glaser writes in the PDF linked above, “We can image deep space and the formation of stars, but at present we have great difficulty imaging even tens of meters into the earth. We want to develop the Hubble into, not away from, the earth.”

Artificially geomagnetized flocks of migratory birds, like “GPS pigeons,” used as distributed earth-anomaly detectors in the name of experimental archaeology.

I’ve long been fascinated by what I might call the geological nature of harddrives – how certain mineral arrangements of metal and ferromagnetism result in our technological ability to store memories, save information, and leave previous versions of the present behind.

A harddrive would be a geological object as much as a technical one; it is a content-rich, heavily processed re-configuration of the earth’s surface.

[Image: Geometry in the sky. “Diagram showing conceptual photographs of how satellite versus star background would appear from three different locations on the surface of the earth,” courtesy of the Office of NOAA Corps Operations (ONCO)].

This reminds me of another ongoing fantasy of mine, which is that perhaps someday we won’t actually need harddrives at all: we’ll simply use geology itself.

In other words, what if we could manipulate the earth’s own magnetic field and thus program data into the natural energy curtains of the planet?

The earth would become a kind of spherical harddrive, with information stored in those moving webs of magnetic energy that both surround and penetrate its surface.

This extends yet further into an idea that perhaps whole planets out there, turning in space, are actually the harddrives of an intelligent species we otherwise have yet to encounter – like mnemonic Death Stars, they are spherical data-storage facilities made of content-rich bedrock – or, perhaps more interestingly, we might even yet discover, in some weird version of the future directed by James Cameron from a screenplay by Jules Verne, that the earth itself is already encoded with someone else’s data, and that, down there in crustal formations of rock, crystalline archives shimmer.

I’m reminded of a line from William S. Burroughs’s novel The Ticket That Exploded, in which we read that beneath all of this, hidden in the surface of the earth, is “a vast mineral consciousness near absolute zero thinking in slow formations of crystal.”

“A pair of laser beams is used to write data into discs of light-sensitive plastic, with both aiming at the same spot,” the article explains. “One beam shines continuously, while the other pulses on and off to encode patches that represent digital 0s and 1s.”

The question, then, would be whether or not you could build a geotechnical version of this, some vast and slow-moving machine – manufactured by Komatsu – that moves over exposed faces of bedrock and “encodes” that geological formation with data. You would use it to inscribe information into the planet.

But it’d be like some new form of plowing in which the furrows you produce are not for seeds but for data. An entirely new landscape design process results: a fragment of the earth formatted to store encrypted files.

Like something out of H.P. Lovecraft – or the most unhinged imaginations of early European explorers – future humans will look down uneasily at the earth they walk upon, knowing that vast holograms span that rocky darkness, spun like inexplicable cobwebs through the planet.

Beneath a massive stretch of rock in the remotest state-owned corner of Nevada, top secret government holograms await their future decryption.

In her recent biography of Sir Christopher Wren – whose towers, domes and steeples appear in the image above – Lisa Jardine describes how she discovered that the London Monument, designed in 1677 by Wren and Robert Hooke together, is actually “a unique, hugely ambitious, vastly oversized scientific instrument” that uses “strategically placed vents and vantage points” to function as a multi-purpose observation deck and lab for measuring atmospheric pressure.

While I was living in Berlin a few years ago, it struck me once that the U-Bahn system could pass, in its own way, for a different kind of “hugely ambitious, vastly oversized scientific instrument” – before I realized, of course, that the Tube, the Metro, the NY subway, etc. – the Beijing underground, Prague, Rome and so forth – all of them could pass for such “scientific instruments.”

In other words, those buried urban routes, with all their circuits linked and cross-connected into electrically mechanized networks that passed through mineral deposits and solid bedrock – including the various branches of late-night service that maintained more or less perpetual motion, humming and soaring through manmade canyons beneath parks and plazas and apartment blocks, as if to imply that the global geotechnical industry had been taken over by AthanasiusKircher –

I realized that, in all that tumult of foundations and energy, you could, if you wanted to, listen for the subtle, cello-like moan of distant trains; and it occurred to me that the whole system, the entirety of the Berlin U-Bahn, could pass for a working model of the universe. A sonic model, at the very least, of the so-called Cosmic Microwave Background Radiation. A vaulted hum, reverbing back and through itself beneath the city.

Or – and this next idea is only slightly less ridiculous, for you cynics out there – it occurred to me that if the U-Bahn system could somehow be hooked up to massive, earth-anchored magnets, and made, therefore, to produce a magnetic field of its own, that you could transform all of Berlin into a geomagnetic harddrive.

As a sail traps the wind, a planetary harddrive would use geomagnetism.

Provided constant motion on behalf of the trains, I thought, and given absolutely gigantic magnets of the right polarity and location, Berlin could start producing its own magnetic field – which meant that any city with a subway could be transformed into a harddrive. Harddrive London. Harddrive Beijing.

Harddrive Moscow.

Of course, it’s obvious even to me that you’d have to do quite a lot more than just bury some magnets underground in order to transform a city into a harddrive – you’d need a shovel, for instance, and perhaps some strong anti-manic drugs; but my point is that if Christopher Wren could build a tower that simultaneously memorialized the Great Fire of London even as it acted as a scientific device, then perhaps you could turn urban infrastructure itself into a kind of working scientific apparatus.